<template>
  <div class="type-nav">
    <div class="container">
      <div @mouseleave="leaveShow()" @mouseenter="enterShow()">
        <h2 class="all">全部商品分类</h2>
        <transition name="sort">
          <!--三级联动-->
          <div class="sort" v-show="show">
            <div class="all-sort-list2">
              <div class="item" v-for="(c1, index) in categoryList" :key="c1.catId"
                   :class="{cur:currentIndex===index}">
                <h3 @mouseenter="changeIndex(index)">
                  <a :data-categoryName="c1.name" :data-category1Id="c1.catId">{{ c1.name }}</a>
                </h3>
                <!--二级，三级分类-->
                <div class="item-list clearfix" :style="{display:currentIndex===index?'block':'none'}">
                  <div class="subitem" v-for="(c2, index) in c1.children" :key="c2.catId">
                    <dl class="fore">
                      <dt>
                        <a :data-categoryName="c2.name"
                           :data-category2Id="c2.catId">{{ c2.name }}</a>
                      </dt>
                      <dd>
                        <em v-for="(c3, index) in c2.children" :key="c3.catId">
                          <a :data-categoryName="c3.name"
                             :data-catalog3Id="c3.catId"
                             @click="goSearch">{{ c3.name }}</a>
                        </em>
                      </dd>
                    </dl>
                  </div>
                </div>
              </div>
            </div>
          </div>
        </transition>
      </div>

      <nav class="nav">
        <a href="###">服装城</a>
        <a href="###">美妆馆</a>
        <a href="###">乐优商城超市</a>
        <a href="###">全球购</a>
        <a href="###">闪购</a>
        <a href="###">团购</a>
        <a href="###">有趣</a>
        <a href="###">秒杀</a>
      </nav>
    </div>
  </div>
</template>

<script>
import {mapState} from 'vuex';
import throttle from "lodash/throttle"

export default {
  name: "TypeNav",
  components: {},
  props: {},
  data() {
    return {
      currentIndex: -1,            /*存储用户鼠标移上哪一个一级分类*/
      show: true                   /*三级联动显示与隐藏*/
    }
  },
  //计算属性 类似于data概念
  computed: {
    ...mapState({
      categoryList: state => state.home.categoryList
    })
  },
  //监控data中的数据变化
  watch: {},
  //方法集合
  methods: {
    //鼠标进入,记录一级分类索引值
    changeIndex: throttle(function (index) {
      this.currentIndex = index
    }, 50),
    //点击三级分类，跳转到搜索页面
    goSearch(event) {
      let element = event.target;
      let {categoryname, category1id, category2id, catalog3id} = element.dataset
      if (categoryname) {
        //整理路由跳转的参数
        let location = {name: "search"}
        let query = {categoryName: categoryname}
        if (category1id) {
          query.category1Id = category1id
        } else if (category2id) {
          query.category2Id = category2id
        } else if (catalog3id) {
          query.catalog3Id = catalog3id
        }
        //路由跳转，如果有params参数，也要传递
        if (this.$route.params) {
          location.params = this.$route.params
          location.query = query
          this.$router.push(location)
        }
      }
    },
    //当鼠标移入的时候，让商品分类列表进行展示
    enterShow() {
      this.show = true
    },
    //鼠标移除
    leaveShow() {
      //清除索引值
      this.currentIndex = -1
      if (this.$route.path !== "/home") {
        this.show = false
      }
    }
  },
  //生命周期 - 创建完成（可以访问当前this实例）
  created() {
  },
  //生命周期 - 挂载完成（可以访问DOM元素）
  mounted() {
    //如果不是Home路由组件，将typeNav隐藏
    if (this.$route.path !== "/home") {
      this.show = false
    }
  },
  //生命周期 - 创建之前
  beforeCreate() {
  },
  //生命周期 - 挂载之前
  beforeMount() {
  },
  //生命周期 - 更新之前
  beforeUpdate() {
  },
  //生命周期 - 更新之后
  updated() {
  },
  //生命周期 - 销毁之前
  beforeDestroy() {
  },
  //生命周期 - 销毁完成
  destroyed() {
  },
  //如果页面有keep-alive缓存功能，这个函数会触发
  activated() {
  }
};
</script>

<style scoped lang="less">
.type-nav {
  border-bottom: 2px solid #e1251b;

  .container {
    width: 1200px;
    margin: 0 auto;
    display: flex;
    position: relative;

    .all {
      width: 210px;
      height: 45px;
      background-color: #e1251b;
      line-height: 45px;
      text-align: center;
      color: #fff;
      font-size: 14px;
      font-weight: bold;
    }

    .nav {
      a {
        height: 45px;
        margin: 0 22px;
        line-height: 45px;
        font-size: 16px;
        color: #333;
      }
    }

    .sort {
      position: absolute;
      left: 0;
      top: 45px;
      width: 210px;
      height: 461px;
      position: absolute;
      background: #fafafa;
      z-index: 999;

      .all-sort-list2 {
        .item {
          h3 {
            line-height: 22.5px;
            font-size: 14px;
            font-weight: 400;
            overflow: hidden;
            padding: 0 20px;
            margin: 0;

          }

          a {
            color: #333;
            cursor: pointer;
          }

          .item-list {
            display: none;
            position: absolute;
            width: 734px;
            min-height: 460px;
            background: #f7f7f7;
            left: 210px;
            border: 1px solid #ddd;
            top: 0;
            z-index: 9999 !important;

            .subitem {
              float: left;
              width: 650px;
              padding: 0 4px 0 8px;

              dl {
                border-top: 1px solid #eee;
                padding: 6px 0;
                overflow: hidden;
                zoom: 1;

                &.fore {
                  border-top: 0;
                }

                dt {
                  float: left;
                  width: 54px;
                  line-height: 22px;
                  text-align: right;
                  padding: 3px 6px 0 0;
                  font-weight: 700;
                }

                dd {
                  float: left;
                  width: 415px;
                  padding: 3px 0 0;
                  overflow: hidden;

                  em {
                    float: left;
                    height: 14px;
                    line-height: 14px;
                    padding: 0 8px;
                    margin-top: 5px;
                    border-left: 1px solid #ccc;
                  }
                }
              }
            }
          }

          //&:hover {
          //  .item-list {
          //    display: block;
          //  }
          //}
        }

        .cur {
          background-color: skyblue
        }
      }
    }

    //三级分类，过渡动画，进入开始
    .sort-enter {
      height: 0px;
    }

    //三级分类，过渡动画，进入结束
    .sort-enter-to {
      height: 461px;
    }

    //动画时间，速率
    .sort-enter-active {
      transition: all .5s linear;
    }
  }
}
</style>
